We have a house built circa 1805 (not listed), it has been converted with many additions. It sits on and up against sandstone. Some of the external walls are single skin and all but one of the downstairs rooms have had concrete floors put in.
We have had an internal wall knocked down and we are now looking at taking up one of these concrete floors that sits next to a Victorian tiled floor. The concrete appears to be about 2″ thick. It butts up to walls on three sides which are all suffering from rising damp and penetrating damp with heavy salt deposits (I assume from the sandstone).
There is very little plaster left on the walls in this space and one of them has been treated by a professional timber and damp company (due to a retention on the mortgage). We are planning to get the walls re-plastered but want to approach the issue of the damp in the most economical (but also with long lasting results) way possible as the we still have 4 more rooms to sort out with this same damp issue (not to mention the re-decoration of all up-stairs rooms).
I have read that due to the age of the property, the aim should not be to remove all drafts, nor replace the concrete that has been put down due to the fact that it will sit on a DPC which will displace the damp back to the walls, or if we do, not allow the concrete to touch the walls, leaving a gap between wall and concrete to allow damp to evaporate.
So, can anybody recommend what I can put on the floor if not concrete with a DPC and insulation? The plan is for the removed floor to be covered with tiles. Again, is there any type of tile we should look to get to assist the evaporation process?